I've heard that it's the shoulders that make girls look bulky, but I agree it's not necessary to make one's arms as thick round as tree limbs.

Besides, girls are naturally not as strong in the upper body as boys. Haruman says, anyway. And he says that you can be muscular and slim at the same time. Eating right and all that.

Still. I did want to make sure I've got at least as many sit-ups and all as Thomas and Zabini.